Resumen de Thermodynamic characterization of dexamethasone sodium phosphate and its complex with dna as studied by conductometric and spectroscopic techniques
Afzal Shah, Asad M Khan, Muhammad Usman, RUMANA QURESHl, Muhammad Siddiq, Syed S Shah
Electrical conductivities were measured to calculate critical aggregation concentration (cac) of dexamethasone sodium phosphate (DSP) at various temperature from 298-313K with an increment of 5 K and in this way its thermodynamic parameters like Gibbs energy of aggregation ( ΔGagg), enthalpy of aggregation (ΔHagg ) and entropy of aggregation (ΔSagg) were estimated. The results demonstrate that DSP forms enthalpy driven aggregates through open association process. Furthermore, its interaction with DNA was studied by UV-Vis spectroscopy. The binding constant of DSP-DNA interaction was evaluated at 298 K and 310 K. Gibbs energy of drug-DNAcomplexation was determined by ΔG= -RT 1n k b , enthalpy of its interaction (ΔH) and entropy of adduct formation (ΔS) were obtained from Van't Hoff equation.
